Drip irrigation is commonly used to supply irrigation to landscaping and crops. Drip irrigation emitters are generally known in the art for use in delivering irrigation water to a precise point at a predetermined and relatively low flow rate, thereby conserving water. The drip emitter taps a portion of the relatively high pressure irrigation water from a supply tube for flow through a typically long tortuous flow duct path to achieve a desired pressure drop prior to discharge at a target trickle or drip flow rate.
In a conventional system, a large number of drip emitters are mounted at selected positions along the length of the irrigation supply tube to deliver the irrigation water to a large number of specific points, such as directly to a plurality of individual plants. More specifically, a number of drip emitters are fitted into a conduit and spaced apart at appropriate distances depending on the desired amount of irrigation. Each emitter includes an inlet to receive water flowing through the conduit, an outlet to emit water from the conduit at a specific rate for irrigation, and a body member intermediate-the inlet and the outlet and that defines the flow duct path.
Tortuous flow duct paths generally include a number of alternating, flow baffles defining a flow channel and causing frequent, regular, and repeated directional changes in water flow. Accordingly, the water flow takes on a back and forth zigzag pattern. The water experiences multiple directional changes as it is constantly redirected through the tortuous flow duct path. This repeated redirection significantly reduces the water pressure and water flow by the time the water reaches the end of the flow duct path.
Experience, however, has revealed that pressure compensating drip emitters may get clogged during operation when they are exposed to water with contaminants. Organic agents and grit, such as algae, also can clog up an emitter and cause the emitter to be unusable. Algae can accumulate in the emitter path both as a result of entering with the water and from growth inside the emitter. Thus, even if the flow path through the emitter is sufficient to pass grit along, it may not pass the grit if algae is present. Accordingly, there is desired a design that permits enhanced flow through the emitter of organic materials, grit and algae to reduce the amount of obstruction and the tendency of emitter clogging.
Further, it has been determined that drip emitters tend to become obstructed in the tortuous flow path when grit tends to become lodged between alternating baffles. Also, even more commonly, drip emitters tend to become obstructed near the emitter outlet. Accordingly, there is desired a design that reduces the obstruction of the emitter at both of these locations.